The standard form of the periodic table shown here includes periods (shown horizontally) and groups (shown vertically). The properties of elements in groups are similar in some respects to each other.

There is no one single or best structure for the periodic table but by whatever consensus there is, the form used here is very useful and the most common. The periodic table is a masterpiece of organised chemical information and the evolution of chemistry's periodic table into the current form is an astonishing achievement.

The International Union of Pure and Applied Chemistry (IUPAC) confirmed the names of elements 113, 115, 117, and 118 as:

On 1 May 2014 a paper published in Phys. Rev. Lett by J. Khuyagbaatar and others states the superheavy element with atomic number Z = 117 (ununseptium) was produced as an evaporation residue in the 48Ca and 249Bk fusion reaction at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. The radioactive decay of evaporation residues and their α-decay products was studied using a detection setup that allows measurement of decays of single atomic nuclei with very short half-lives. Two decay chains comprising seven α-decays and a spontaneous fission each were identified and assigned to the isotope 294Uus (element 117) and its decay products.